Will the tag sort ultimately stick when we switch to a different view and back? Right now if I apply a sort and then go to look at, say, Dates, then when I go back to Tags the tag sort has gone back to default a-z.

@whitten: As it is now, all tags are on the same level. And I think there is no plan to change that. You could use a workaround like "music_piano, "music_guitar". Subtasks would probably intefere with the Grid view too.